In general, chronic dialysis catheters are fixed-length, dual-lumen catheters that cannot be trimmed or adjusted at either the distal or proximal ends. These types of catheters are tunneled under the skin to a venotomy site and placed in a large central vein (e.g., the jugular vein).
The process of determining the proper length for the tunnel (i.e., length from outside the body to the venotomy site) and the proper length catheter for placement in the vein to ensure that the tip is at the desired location (e.g., the right atrium or the superior vena cava and right atrial, or SVC/RA, junction) is quite crude and imprecise. Typically, a physician places the catheter on the exterior of the patient's body and estimates the location of the heart. The catheter is then stretched out to emulate the tunnel. This crude process is used by the physician to obtain the "proper" length for the catheter.
A problem with this approach, however, is that it does not always provide the physician with the exact catheter tip placement that he/she desires. In addition, chronic dialysis catheters come in various lengths to suit different anatomical needs, and the sterile catheter kit that has been opened sometimes contains a catheter that is too short or too long. Further, sterile catheter kits must then be opened until the proper length catheter is found, thereby wasting catheters and increasing costs. Another problem with this approach is that the physician may create a tunnel of incorrect length and then need to create a new tunnel suitable for the catheter length selected. Creating a new tunnel increases the risk of infection and hematoma and increases the procedure time.